〔Abstract〕 Objective To investigate the expression of nm23 protein and E-cadherin in breast cancer and their relationship with clinicopathological characteristics. Methods Ninety one patients with breast cancer who were admitted to Putian 95 Hospital from January 2020 to December 2022 were selected as the study subjects. All patients were treated with surgery. Tumor tissues and normal tissues adjacent to cancer were collected during surgery. Immunohistochemical streptavidin peroxidase (SP) method was used to detect the expression of nm23 and E-cadherin in tumor tissues and normal tissues adjacent to cancer. The relationship between the expression of nm23 and E-cadherin and pathological features such as age, maximum tumor diameter, lymph node metastasis, tumor staging, and menopausal status was aralyzed. Results The positive expression rate of nm23 protein in tumor tissue was lower than that in adjacent normal tissue, and the positive rate of E-cadherin was higher than that in adjacent normal tissue, with statistical significance (P < 0.05); The proportion of patients with nm23 positive expression who had a maximum tumor diameter of ≥ 3 cm, lymph node metastasis, and tumor stages III-IV was lower than those of nm23 negative patients, and the differences were statistically significant (P < 0.05), while the expression of E-cadherin was opposite to nm23. Conclusion The expression of nm23 protein is low and the expression of E-cadherin is high in breast cancer. The expression of nm23 protein and E-cadherin is closely related to tumor stage and lymph node metastasis, which may be a new target for clinical treatment.